They win six games in a row… only to lose their next six. They lose Rajon Rondo for the rest of the season… only to lose Jared Sullinger two games later. They run off a surprising seven-game win streak, beating the Miami Heat, Los Angeles Clippers and Denver Nuggets… only to have it snapped by the cellar-dwelling Charlotte Bobcats Monday night.

It could not possibly get any worse for the Celtics, could it?

Wrong.

With seconds remaining in the third quarter, Leandro Barbosa’s leg buckled from underneath him following a drive. He immediately fell to the floor clutching his left knee and had to be helped off the court.

It’s an unfortunate setback for Barbosa, who seemed to be benefiting the most from Rondo’s absence.

In eight games since, he was averaging 8.1 points and 2.8 assists per game in 21.2 minutes a night. A vast improvement from the 4.5 points per game he was averaging in just under 10 minutes an outing.

What It Means

With Barbosa out, Boston will be losing one of their most productive players in the wake of Rondo’s injury.

In that eight-game span, Barbosa combined with Jeff Green and Jason Terry to provide the best three-man grouping for the team. The trio was plus-28 in 147 minutes on the floor together—the next highest grouping was only plus-four. (per ESPN Boston)

But while losing Barbosa’s production will certainly hurt the Celtics moving forward, it also decreases their already depleted number of trade chips. The team now only has 10 healthy players on the roster.

With Boston in desperate need of additional pieces, Barbosa looks to be the most likely player to be involved in any trade talks before the upcoming Feb. 21 deadline. If not, there’s also a strong possibility the team might consider buying out Barbosa to open up a roster space.

Signed to a one-year, veteran-minimum deal, Barbosa would be a low-cost option for a team that already has two other season-ending injuries (Rondo and Sullinger) taking up roster space.

Such a move would make way for the Celtics to possible offer a 10-day contract to Shelvin Mack of the Maine Red Claws. Sorry, Delonte West is not an option (per Adrian Wojnarowski of Yahoo Sports).

In 17 games for Boston’s D-League affiliate, Mack has averaged 19.6 points, 7.6 assists and 4.7 rebounds per game in 39.8 minutes a night. He’s shooting 46.2 percent from the floor and connecting on 38.3 percent of his attempts from distance.

Mack, who has played 75 career games in the NBA, would be a great fit for the team.

Regardless, the loss of Barbosa is sure to set the Celtics back a bit.